Some readers have asked how to make the alteration to a raglan sleeve that needs more cap height.
I used the sleeve from Vogue pattern 8146 that Mary Beth used in Critique by Els Muslin by Mary Beth
If a raglan sleeve shows diagonal wrinkles it needs more cap height. You can alter the pattern and add the amount you need to fill up this shortage of length which causes the diagonal wrinkles.
To measure how much sleeve cap height you need to add,(see diagonal sleeve wrinkles) undo the basting from the underarm sleeve and move the sleeve upwards with one hand ( higher at armpit) until you notice that the diagonal wrinkles are gone. Measure the amount you moved the sleeve upwards, from the stitch line at armpit towards the stitch line at sleeve underarm.
Mary Beth sent me a picture of the sleeve pattern she used,
I traced the pattern picture to use as an example for the alteration and marked the seam allowances,
Draw a line from the notch at the front and back sleeve arm scye towards the shoulder stitch line notch which indicates the end of the shoulder. Removed the seam allowances at the upper part of the sleeve pattern .
Slash the line from the shoulder notch towards the notch at arm scye back and front and add the amount you need,
You can see how the added length for the sleeve cap height differs from the original used pattern.
The red line shows the new altered raglan sleeve pattern, the blue line is the original one. The straight of grain needs to be lenghtened for the upper part as well as adding the seam allowances back on.